There are no tubes in a TransOceanic 3000-1.
The first thing that I'd try is cleaning the bandswitch (and other controls). If the contacts on the bandswitch are dirty and/or corroded, they can weaken or completely prevent reception. A common problem on all older multi-band radios.
With the chassis out of the cabinet -- careful, it's a tight squeeze -- you want to spritz a bit of good electronic cleaner such as DeOxit onto the bandswitch contacts, then run the switch back and forth through all of its positions several times.
Same treatment for the volume control. If it's full of crud, it can make scratchy noises or just make the radio quiet. There's usually a little opening in the volume control case right where the wires connect to it. Spritz a little bit of cleaner into that opening, then work the volume control all the way back and forth several times.
Let the cleaner evaporate before trying the radio again.
Don't slop cleaner all over the place, and especially avoid spraying it onto the dial markings.
You can get DeOxit at
http://www.tubesandmore.com/ and other suppliers.
I would also carefully clean all of the connecting points in the battery case, as well as the pins on the little plug that plugs into the radio chassis. If your radio doesn't receive enough power, it can't work right. For this, you can use very fine sandpaper. Don't use steel wool -- you really don't want fine metal hairs flying around inside your radio.
Oh -- and if you're using an AC adapter, use DeOxit to clean the plug and the jack. Spritz a little bit of cleaner into the jack, then plug and unplug the adapter a bunch of times.
Again, don't firehose the entire chassis with cleaner. Wipe up any excess with a paper towel and let all the cleaner evaporate before trying the radio again.
These are just the most basic first steps. There might be something else wrong with your radio, but it's pointless to try diagnosing that until you know that it's not simply suffering from a case of cruddy contacts.
Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html